The present invention relates to a fan with axial blades, in particular for radiators of motor vehicles. This general type of fan has been disclosed in commonly assigned DE-A 44 45 671 and EP-A 515 839.
The axial fan according to DE-A 44 45 671 has a cylindrical hub on which an air-guide ring (also called a cap) is arranged at the front end in order to improve the incident flow. This cap divides the air flow into a main flow via the hub and a secondary flow via the viscous fluid friction clutch, but this entails special design measures with regard to the secondary flow and increased pressure losses. According to EP-A 515 839, the fan hub has a so-called hub ramp on the pressure side of the axial blades. Although the flow is stabilized on the rear side of the blades by the hub ramp, the flow conditions on the front side of this fan are still capable of being improved, in particular if the fan is fastened to a viscous fluid friction clutch. In such arrangements involving a viscous fluid friction clutch and axial fan, the objective is to bring both flow components, that is the cooling-air flow via the front side of the clutch and the incident flow for the fan hub, together to the greatest extent possible free of disturbance.
One object of the present invention therefore resides in improving the flow conditions for axial fans of the general type mentioned above. It is a particular object of the invention to provide a fan that coordinates the cooling-air flow for the clutch and the incident flow for the fan in an effective manner.
In accomplishing the foregoing objects, there has been provided according to one aspect of the present invention a fan for a motor vehicle radiator, comprising a fan hub; a plurality of axial blades fastened to the fan hub; a plurality of air-guide elements mounted on the hub and arranged in the air-inlet-side region of the hub and extending to the suction side of the axial blades. According to a preferred aspect the fan further includes a hub ramp which rises against the direction of fan rotation provided on the pressure side of each axial blade, and wherein the air-guide elements are arranged upstream of the hub ramps as viewed in the direction of air flow.
There has also been provided a motor vehicle embodying the radiator cooling fan according to the invention.
Further objects, features and advantages of the present invention will become apparent from the detailed description of preferred embodiments that follows, when considered together with the accompanying figures of drawing.